1. Field
Methods and apparatuses consistent with exemplary embodiments relate to image stabilization through image processing, and a zoom camera including an image stabilization function.
2. Description of the Related Art
Recently, many surveillance cameras are installed in buildings and streets to prevent crimes and theft. An image captured by a surveillance camera displays a current state of a place where the surveillance camera is installed through a monitor in a police station or a management office of a building. In general, a surveillance camera has a zoom function to enlarge or reduce an object to provide lots of user convenience.
However, in the surveillance camera having the zoom function, an optical axis error occurs when an imaging device, such as a plurality of lens groups and a charge-coupled device (CCD), is assembled in the surveillance camera or due to various factors such as a tolerance of an optical system, and thus, an optical axis of the surveillance camera is changed according to zoom change.
FIGS. 1A to 1C are images showing when an optical axis error occurs in an image captured by a zoom camera.
Referring to FIG. 1, a portion marked with ‘+’ in FIG. 1A represents a central area of the image. However, comparing the image of FIG. 1A with the image of FIG. 1B captured by zooming-in the zoom camera, the central area marked with ‘+’ of FIG. 1A is moved as shown in FIG. 1B, which shows that an optical axis error occurs. Accordingly, as shown in FIG. 1C, there is a need for a method of compensating for the optical axis error so that the central area of the image is maintained at its original position even after the image is enlarged.
In general, a method of mechanically image stabilization has been provided. However, this method has a problem that if a physical impact is applied to a camera after compensating for the optical axis error or if a long time elapses, a physical compensation should be applied to the camera again.